8265767: compiler/eliminateAutobox/TestIntBoxing.java crashes on arm32 after 8264649 in debug VMs

[huishi-hs]

This patch fix failure exposed by JDK-8264649.

compiler/eliminateAutobox/TestIntBoxing.java crashes on arm32 in Compile::check_no_dead_use assertion.
In LoadNode::eliminate_autobox, early "result" is dead after line 1450 but not added into PhaseGVN worklist for optimization.
Its out_cnt is 0. If it isn't removed, will trigger assertion in Compile::check_no_dead_use.

1443             } else if (result->is_Add() && result->in(2)->is_Con() &&
1444                        result->in(1)->Opcode() == Op_LShiftX &&
1445                        result->in(1)->in(2) == phase->intcon(shift)) {
1446               // We can't do general optimization: ((X<<Z) + Y) >> Z ==> X + (Y>>Z)
1447               // but for boxing cache access we know that X<<Z will not overflow
1448               // (there is range check) so we do this optimizatrion by hand here.
1449               Node* add_con = new RShiftXNode(result->in(2), phase->intcon(shift));
                       --- result before is  dead and might not removed
1450               result = new AddXNode(result->in(1)->in(1), phase->transform(add_con)); 
1451             } else 

Detail analysis is in https://bugs.openjdk.java.net/browse/JDK-8265767

@mychris I have verified compiler/eliminateAutobox/TestIntBoxing.java on qemu, it failed with same assertion and now passes with this fix. Would you please help verify it on arm32 machine?

Testing:

• Passed Tier1-3 on Linux x86_64, release and fastdebug build, default option and -XX:-TieredCompilation.
• compiler/eliminateAutobox/TestIntBoxing.java on arm32 release/fastdebug/slowdebug

---

Progress

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Issue

• JDK-8265767: compiler/eliminateAutobox/TestIntBoxing.java crashes on arm32 after 8264649 in debug VMs

Reviewers

• Vladimir Kozlov (@vnkozlov - Reviewer)
• Tobias Hartmann (@TobiHartmann - Reviewer)

Reviewing

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[bridgekeeper]

👋 Welcome back hshi! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@huishi-hs The following label will be automatically applied to this pull request:

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[mlbridge]

Webrevs

• 01: Full - Incremental (f25b3838)
• 00: Full (cfc353ed)

[vnkozlov]

The fix is reasonable.
Add comment // remove dead node later
Pass PhaseIterGVN* igvn instead of eliminate_autobox(PhaseGVN* phase) to simplify code. Note, can_reshape == true only for PhaseIterGVN.

[huishi-hs]

The fix is reasonable.
Add comment // remove dead node later
Pass PhaseIterGVN* igvn instead of eliminate_autobox(PhaseGVN* phase) to simplify code. Note, can_reshape == true only for PhaseIterGVN.

@vnkozlov Thanks for your review! All comments are fixed and pass Tier1-3 on Linux x86_64, release and fastdebug build, default option and -XX:-TieredCompilation.

[vnkozlov]

Good.

[openjdk]

@huishi-hs This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8265767: compiler/eliminateAutobox/TestIntBoxing.java crashes on arm32 after 8264649 in debug VMs

Reviewed-by: kvn, thartmann

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 29 new commits pushed to the master branch:

• 3544a9d: 8266391: Replace use of reflection in jdk.internal.platform.Metrics
• 020236c: 8264786: [macos] All Swing/AWT apps cause Allow Notifications prompt to appear when app is launched
• 45760d4: 8266320: (bf) ReadOnlyBufferException in heap buffer put(String,int,int) should not be conditional
• ff65920: 8265491: Math Signum optimization for x86
• 55cc0af: 8266185: Shenandoah: Fix incorrect comment/assertion messages
• 880c138: 8265349: vmTestbase/../stress/compiler/deoptimize/Test.java fails with OOME due to CodeCache exhaustion.
• 001c514: 8265322: C2: Simplify control inputs for BarrierSetC2::obj_allocate
• 194bcec: 8265984: Concurrent GC: Some tests fail "assert(is_frame_safe(f)) failed: Frame must be safe"
• 1d9ea3a: 8266083: Shenandoah: Consolidate dedup/no dedup oop closures
• 80941f4: 8234446: Post-CMS workgroup hierarchy cleanup
• ... and 19 more: https://git.openjdk.java.net/jdk/compare/07ecd421d1538ae53ffbea65eccfa938e19a9f0f...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

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➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[mychris]

Thanks for looking into this issue.
I am currently testing on an ARMv7-A target, and compiler/eliminateAutobox/TestIntBoxing.java is passing now 👍. The whole hotspot tier1 suite will take some time, so I will report back later today, or tomorrow.

[mychris]

Hi @huishi-hs, hotspot tier1 passes on my ARMv7-A targets.

[huishi-hs]

@mychris Thanks for help verification!
@vnkozlov Thanks for review!
Does this patch need a second review before integrate?

[TobiHartmann]

Looks good to me too.

[huishi-hs]

@TobiHartmann Thanks!

[huishi-hs]

/integrate

[openjdk]

@huishi-hs
Your change (at version f25b383) is now ready to be sponsored by a Committer.

[TobiHartmann]

/sponsor

[openjdk]

@TobiHartmann @huishi-hs Since your change was applied there have been 37 commits pushed to the master branch:

• 05e6017: 8265137: java.util.Random suddenly has new public methods nowhere documented
• aa90df6: 8266187: Memory leak in appendBootClassPath()
• b651904: 8266438: Compile::remove_useless_nodes does not remove opaque nodes
• 141cc2f: 8261527: Record page size used for underlying mapping in ReservedSpace
• 8e071c4: 8265784: [C2] Hoisting of DecodeN leaves MachTemp inputs behind
• ce1bc9d: 8266432: ZGC: GC allocation stalls can trigger deadlocks
• 30ccd80: 8264950: Set opaque for JTooltip in config file of NimbusLookAndFeel
• cfdf4a7: 8266449: cleanup jtreg tags in compiler/intrinsics/sha/cli tests
• 3544a9d: 8266391: Replace use of reflection in jdk.internal.platform.Metrics
• 020236c: 8264786: [macos] All Swing/AWT apps cause Allow Notifications prompt to appear when app is launched
• ... and 27 more: https://git.openjdk.java.net/jdk/compare/07ecd421d1538ae53ffbea65eccfa938e19a9f0f...master

Your commit was automatically rebased without conflicts.

Pushed as commit ee5bba0.

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